Fossil fuels are a limited resource that has allowed the development and sustenance of the current society, as we know it. However, its massive exploitation has led us to the current situation in which, as we all know, in a not very long period we will deplete the available oil reserves.
What we could call the oil era reached its peak in 1970. At that time, for every barrel of oil (its energy equivalent), 200 barrels of oil were obtained. Currently, this figure has dropped to 20 barrels of oil for every barrel used. In the near future, it is expected that this figure will decrease even further, to 5 barrels per barrel used, at which point the exploitation of oil will begin to reach its profitability limit.
At that moment, as we say very close, it will be necessary to look for new sources of energy at a global level to maintain the current energy demands. If we want to establish a truly sustainable society, it is inevitable that these new sources are renewable and their exploitation is as respectful as possible to the environment. However, the first analysis to be carried out is, obviously, the energy capacity available from these sources in relation to global energy demand, in order to determine the real viability of the different alternatives.
Next, we present a list of the main sources of energy, with the maximum amount of energy that can be obtained from their exploitation:
- Nuclear energy: 0.15 times global demand.
- Hydroelectric energy: 0.33 times global demand.
- Geothermal energy: 5 times global demand.
- Wind energy: 20 times global demand.
- Solar energy: 4000 times global demand.
It is clear that a change is possible, through a combination of available technologies. However, humanity is not doing its homework. Estimates indicate that in order to change society to a sustainable model before fossil fuel reserves are exhausted, it would be necessary to build 149 square meters of solar power plants every second, 1 large wind generator every 3 minutes, and 1 nuclear power plant every week. Values, all of them, far from reality.
The situation worsens if we take into account the increase in global consumption. While there is a trend to reduce population growth, the increase in per capita energy consumption experiences a much larger increase. Of the total population of China, more than 1 billion people, only 20% are considered middle class. It is estimated that in the next 10 years, this figure will increase to 40%. On the other hand, in India, with a population of 600 million (twice that of the US), 40% will reach the middle class within 15 years.
Humanity faces a challenge of enormous dimensions, led by the US, China, and Spain as the main investors in renewable energies. A sustainable future is inevitably possible through the improvement of energy efficiency and the intelligent use of renewable energy sources.